This invention relates to a quick connect/disconnect driveline assembly for facilitating service, repair, and change-out operations that occur over the life of the driveline. Specifically, the invention includes a retaining ring for engaging and retaining a bearing at a proper location on a shaft while allowing a yoke member to be separately mounted on the shaft. The yoke member can be connected and disconnected without having to remove the retaining ring.
Most vehicle drivelines include drive axles that are connected to a driveshaft or other driveline component with a universal joint. The drive axle can be either a single drive axle coupled to the driveshaft or a tandem axle assembly including a forward-rear axle that is coupled to the driveshaft and a rear-rear axle that is connected to the forward-rear axle via an interaxle driveshaft. Universal joints provide connections between the axles and the driveshafts.
The universal joint allows two shaft components to be oriented at different angles relative to each other to accommodate relative movement and angular misalignment while transmitting torque. The universal joint connections are used to interconnect driveline components that are not mounted to the vehicle in a straight line.
For example, the driveshaft powered by a vehicle engine provides input, via a transmission, to a center gear assembly of the single drive axle. The center differential has an input pinion shaft that is coupled to the driveshaft with a universal joint assembly. In another example, the driveshaft provides input to the tandem axle having the forward-rear axle connected to the rear-rear axle with the interaxle driveshaft. The forward-rear axle has an input pinion shaft coupled to the driveshaft and an output thru-shaft coupled to the interaxle driveshaft. The rear-rear axle has an input pinion shaft that is coupled to the interaxle driveshaft. Universal joint assemblies connect both axles to the interaxle driveshaft as well as connecting the driveshaft to the input pinion shaft of the forward-rear axle.
The universal joints typically include a pair of yoke members. One yoke member is supported on a shaft (i.e., the input pinion shaft and/or the output thru-shaft) operably connected to one of the axles and the mating yoke member is supported on the driveshaft or interaxle driveshaft. Bearing assemblies are mounted within the axles to rotatably support the input pinion shafts and the output thru-shaft. Typically the yoke members, which are supported on the input pinion shafts and the output thru-shafts, have a hub portion that slides over the shaft abuts against the bearing assembly. A nut is then threaded on the shaft and tightened to hold the yoke member securely against the bearing assembly.
In some applications, the nut is tightened to hold the yoke member securely against the bearing assembly to properly retain and position the bearing assembly on the appropriate shaft. In a tandem axle configuration, the yoke members are installed on the output thru-shaft and the input pinion shaft to the rear-rear axle and the respective nuts are tightened against the yoke members to retain the bearings. The interaxle driveshaft is then installed between the forward-rear axle and the rear-rear axle. The interaxle driveshaft is a two-piece telescoping shaft that is collapsed to a shorter length, inserted between the axles and then expanded to the desired length for attachment to the yoke members on the thru-shaft and input pinion shaft to the rear-rear axle. This installation processes is difficult and time consuming. Thus, it would be desirable to simplify the installation process of the yoke members on the shafts and the connection of the axles to the interaxle driveshaft.
In other applications, the nut is tightened to a predetermined torque level to provide a preload force for the bearing assembly. Sometimes, a preload force is required for the bearing assembly to operate and wear properly. This configuration is susceptible to having inconsistent torque applied to the nut due to the necessity of removing and reinstalling the yoke member for service. In other words, once a yoke member is removed for service, the preload force needs to be re-applied to the bearing assembly. When the yoke member is re-installed, the nut can be over or under-tightened resulting in an improper bearing preload force, which can lead to diminished performance, increased noise, accelerated wear, and pre-mature failure. This situation can occur when the yoke members are removed for repair, replacement, and/or when the yokes members are changed-out to accommodate greater or lesser load carrying capacities. Further, the process of removing and re-installing the yoke members and associated retaining nuts is time consuming.
For the above reasons, it would be desirable to simplify the assembly process for connecting and disconnecting yoke members and to eliminate the need to re-apply bearing preload forces after driveline service to avoid premature wear and failure in addition to overcoming other deficiencies in the prior art as outlined above.
A driveline assembly includes a first shaft that is supported on a bearing assembly for rotation within a drive axle. The shaft includes a first mounting portion and a second mounting portion. A retaining ring is installed on the first mounting portion to engage and retain the bearing assembly at a proper position along the shaft. A yoke member is installed on the second mounting portion for connecting the first shaft to a second shaft. To simplify service and assembly, the yoke member can be removed without having to remove the retaining ring from the shaft. Additionally, the yoke member can be re-installed without affecting the retaining ring.
In the preferred embodiment, the first mounting portion comprises a threaded surface on one portion of the shaft and the second mounting portion comprises a splined surface on another portion of the shaft. The retaining ring includes a threaded inner bore that installed in threaded engagement with the threaded surface on the shaft. The yoke member includes a splined inner bore that mates with the splined surface on the shaft.
Preferably, the yoke member includes a quick connect/disconnect device that permits the yoke member to be easily removed for repair, replacement, or change-out. The device includes components that are easily directed between connect and disconnect conditions. In one embodiment, the device includes at least one longitudinally extending slot formed in the body of the yoke member and at least one laterally extending thru-hole. To connect the yoke member to the shaft a clamping member is inserted into the thru-hole and applies a clamping force on opposing edges of the slot to clamp the yoke member to the shaft. To disconnect the yoke member, the clamping force is released.
In another embodiment, the device includes a laterally extending hole in communication, through a small opening, with the splined inner bore of the yoke member. To connect the yoke member to the shaft, a spring loaded pin is biased to engage an edge of the small opening to retain the yoke member on the shaft. To disconnect the yoke member, the spring loaded pin is depressed to disengage the edge of the small opening to permit removal of the yoke member from the shaft.
In some applications, the retaining ring is tightened against the bearing assembly to a predetermined torque level to achieve a predetermined bearing preload. The yoke member is then installed on the shaft. The yoke member is removable from the shaft without having to remove the retaining ring. Thus, the bearing preload force is not affected during driveline maintenance.
The drive axle can be a single drive axle or a tandem drive axle assembly. In the single drive axle configuration, the shaft that supports the retaining ring and yoke member is an input pinion shaft. The pinion shaft supports a pinion gear that is in driving engagement with a center gear assembly in the drive axle. The retaining ring is positioned on the pinion shaft between the yoke member and the pinion gear.
In the tandem drive axle assembly configuration, the assembly includes a forward-rear axle and a rear-rear axle that are interconnected via an interaxle driveshaft. The shaft that supports the retaining ring and yoke member is preferably an output thru-shaft from the forward-rear axle. The thru-shaft is driven by a center gear assembly of the forward-rear axle and is coupled to the interaxle driveshaft. Optionally, or in addition to, the input pinion shaft to the rear-rear axle can also include a yoke member and retaining ring as described above in reference to the single drive axle.
In the preferred embodiment for the tandem axle configuration, the interaxle driveshaft is fixed in length. The yoke member is splined to the thru-shaft of the forward rear axle, as described above, for sliding adjustment along the thru-shaft. Preferably, the interaxle driveshaft is a single piece component that is used in combination with the sliding yoke member to provide variable length adjustment on the thru-shaft.
The subject invention simplifies assembly of driveline components in addition to improving performance. These and other features of the present invention can be best understood from the following specifications and drawings, the following of which is a brief description.